General Question regarding exhaust manifold....

[twistedkittykat]

My 2000 1.2 Fiat Punto needs a new exhaust manifold. The old one only has one lambda sensor above the cat. All the pics I have seen for a new replacement have holes for two sensors. One above and one below the cat. Am I right in thinking it will be supplied with a bolt to fill the lower hole if needed?
Kat x

 

[Scoobysnacks]

I'd suggest that if they have 2 holes they're not the correct unit. But if they fit and you can only get them with 2 holes then there shouldn't be a problem with putting a bolt in the second hole, as long as it's a good tight fit. Probably best to fit it with some thread locking compound to help prevent leaks and keep it in place!

 

[twistedkittykat]

Thank you scoobysnacks much appreciated x

 

[red]

twistedkittykat,

I'm not understanding this. With two lambda sensors, one before and one after the cat, surely only the one before the cat is in the manifold, the other must be in the exhaust pipe after the cat. Are you saying the new manifold has two holes?

red.

 

[Moosey]

Are you sure the lower hole is for a lambda and not for a mounting bracket?

You can buy lambda sensor blanking plugs easily, like this:

http://cgi.ebay.co.uk/M18-X-1-5-Lam...arts_Vehicles_CarParts_SM?hash=item335c489b36

 

[Scoobysnacks]

red. On the mk2 1.2's, the cat is welded directly onto the exhaust manifold, it comes as one unit. A stupid design imho, as if the manifold goes you have to replace the cat too, and vice versa, even if the other bit is perfectly ok!

Not many 1.2 cars I know that cost £300 odd to replace an exhaust manifold!

And Moosey, you might have something there, I think the bottom thing is for mounting the heat shield on? I know I was fuming when I had my cat replaced the f#######s didn't put the heat shield back on, and when I asked them where it was they denied all knowledge of it! Imbeciles!

 

[Moosey]

I should really know this, having fitted one a couple weeks ago, but my memory is shot. I have to do some testing on this car tomorrow, so will take a peek. I have a feeling there is a mounting bracket just below the cat, will have a look tomorrow.

 

[bredsticz]

Older MK2's did only have 1 lambda sensor. I'm selling a manifold and cat atm actually that only had the one sensor. The is also a mounting bracket very close as mentioned

 

[twistedkittykat]

Scoobysnacks is right about the cat being mounted directly onto the exhaust manifold. And yes it is a very stupid design!

Can't post link but have a look on fleebay for: FIAT PUNTO 1.2 Exhaust Manifold Cat Converter 91016. Maybe just a generic pic. But definitely has two holes. And the guy swears it is the correct one.

Plus in the manual it says there is an upper and lower sensor. Which is why I was pretty confused when I could only find one!

Have ordered one from cats2u who matched his price with full fitting kit will be delivered tomorrow so will let everyone know what it looks like then

 

[Moosey]

I saw what you mean about some having two Lambda ports. I assume that's for later MK IIs and MK IIIs. Having two lambdas (1 pre-cat, 1 post-cat.) is to check cat efficiency for emissions control, if the second lambda gets too high an oxygen reading (I think it's too high, maybe too low, don't remember.) it shows that the cat isn't working right an should throw a warning light.

The one on the car i have here has 1 lambda, and it's above the cat on the right. (If you're looking at the front of the car.) The mounting bracket is below, near where it passes under the sump.

After some looking, it seems some OEM cats have the lambda before the cat and others have it after. Maybe the aftermarket cat have two ports so it's compatible with both, and the fitting kit includes a blanking plug. T'is possible..

 

[Scoobysnacks]

Mine is a very early (one of the first actually, '99 on a V plate) mk2, and it only has the one lambda sensor!

 

[red]

On the mk2 1.2's, the cat is welded directly onto the exhaust manifold, it comes as one unit.

Scoobysnacks,

Noted! I was writing up a script for head gasket renewal on a Mk2b a week or two ago (before doing the job - still not done it) and wondered why Haynes said to disconnect the downpipe from the manifold. I was expecting to disconnect the cat from the manifold but obviously can't!

red

 

[Scoobysnacks]

Not without an angle grinder red!

 

[Moosey]

Scoobysnacks,

Noted! I was writing up a script for head gasket renewal on a Mk2b a week or two ago (before doing the job - still not done it) and wondered why Haynes said to disconnect the downpipe from the manifold. I was expecting to disconnect the cat from the manifold but obviously can't!

red

What engine is in yours? I did a 1.2-litre 16v recently. The original headbolts were M10 Ribe, while the aftermarket replacements were M10 Polydrive. (A VAG-only profile..) If it's a 16v an you need to borrow timing tools or anything, just give me a shout.

I have all kinds of goodies in the box!

(And no money because of it..)

 

[Scoobysnacks]

Them's is pretty boxes.

All you gotta do now is get some stuff to put in them!

 

[Moosey]

Them's is pretty boxes.

All you gotta do now is get some stuff to put in them!

It's pretty much full. I've bought another box as i have a shipment of eBay purchases coming from the US soon and don't really have the space in this box. That and i wanted it..

I buy a lot of tools, but it's never enough..

 

[m20b25]

I have a 99 Bravo with a 01 engine (not very fimiliar with the Punto). There is only one oxygen sensor on these cars but the 01 model has 2. So I fitted it on as I had no choice and used an old sensor as a blanking plug. Just cut the wires not the whole assembly.... The centre of the plug I currently use burned out, at low revs the car has a whistle similar to a turbo...

 

[DaveMcT]

My HGT Punto has two precats each with an O2 sensor and another cat under the car floor with another O2 sensor. The precats supposedly help with startup emissions but it gets warm so fast I thinkl they are overkill and waste fuel by blocking the exhaust flow.

 

[Moosey]

My HGT Punto has two precats each with an O2 sensor and another cat under the car floor with another O2 sensor. The precats supposedly help with startup emissions but it gets warm so fast I thinkl they are overkill and waste fuel by blocking the exhaust flow.

VAG cars with the 1.4/1.6 FSI engines have a precat off the manifold and another cat under the car, with two lambdas. I can't imagine that a 1.4-litre 16v FSI engine with EGR is that bad in emissions to warrant two cats. It's odd.

Does your car have two precats, each running off two cylinders?

 

[twistedkittykat]

Highjacked the other halves account seeing as I am the one doing the work on the car

My suspicions were correct. Got the correct part through but unfortunately it has two holes for the sensors as shown in the pic below. I was lucky and have got hold of a second hand lambda sensor that I plan to use to just plug the gap as I was too lazy to hunt down a lambda blanking plug to fit

Unfortunately have also discovered oil is leaking into the clutch and causing it to slip. Joy!